Adjustable film gate



Mamh 6, 193?. R. H. DRAEGER ADJUSTABLE FILM GATE Filed May 9, 1935 'cording to the size oi the object i9 ies? Patented1 ll Claims.

(Granted u:inonder the act oi March 3, i883, as amended April 30, i928; 37d il. G. 757) ".lhis invention relates to an adjustable film gate especially designed for use in copying cameras, projectors, enlargers or the like, wherein varying widths of strip lm may be used acthat is being copied or photographed. i

In copying cameras and the like it is desirable that only that amount of film be exposed las will just hold the image of the object being copied. Ii more film is exposed it is wasted, and besides, the unnecessary expense oi the wasted nlm has the undesirable feature ithat the same number oi images occupy a greater number of feet of iilm, thereby unnecessarily increasing the storage land transportation problem thereof.

With this invention it becomes possible to restrict the amount of nlm that will be exposed as desired, it being intended to restrict the exposed nlm to a size substantially equal to the image being impressed thereon so as to elimihate or keep to the minimum any Wasted areas between successive images.

As a further feature the manual means for adjusting the size of the ilm gate of this invention maybe coupled by a gear train to oper-1 ate an indexing mechanism which will limit the movement or" the nlm between successive images to an amount just suiicient to carry the successive images without wasting nlm therebetween, this index feature being shown and claimed in a copending application :tiled on May 9, i935, Serial No. 20,613, by the same inventor.

With the foregoing and other objects in View as will hereinafter become apparent, this invention comprises a combination and construction hereinafter disclosed, claimed and illustrated on the accompanying drawing, wherein:

Fig. 1 is a sectional View of a copying camera to which this invention has been applied;

Fig. 2 is a top plan view of the lm gate ci this invention;

Fig. 3 is a top plan view of the nlm gate pieces;

Fig. d is an end View only of the iilm gate toggles; and

Fig. 5 is a sectional View of line or Fig. l.

There is shown at it a schematic representation of a copying camera or the like having a lens barrei il through which extends the lens draw tuoe l2. Carried in the camera it in a conventional manner is the nlm stri i3 opern ated by the indexing mechanism lil operated in a conventional manner or according to the copending manner oi the application above re ierred to. The nlm strip i3 is held on the nire gate i5 by means of the pressure plate it secured in the lrn gate cover il, which is hinged as at i8 in the usual manner. Secured beneath the nlm gate cover il is the film gate frame i9 in which is located the lrn gate i5. The film. gate i5 includes a nlm gate piece iii and the second lm gate piece 2l. The nlm gate pieces 2G and 2l are each undercut or slotted as at 22 in other arms 23 and 2G, while their short stubs 25 are provided with flat countersunk ngers 2li adapted tct into the undercut 22 and provide light-tight connection therebetween.

The lm gate pieces Ell and 2l are provided on their bottoms with a pair of transverse grooves 2l into which Will extend fingers 28 oi toggles 2E which are pivoted as at Sii to suitable bosses provided in the lm gate frame i9. As a result of the toggle connections 28 and 2Q and grooves 2l, the linear movement of either nlm piece 2t or il provides a corresponding or opposite linear movement of the other Iilm gate piece.

Secured to one of the lm gate pieces as El is an extension iii which rides in a suitably provided slot in the nlm gate trame lil. Secured to the bottom of this extension 3i is a rack 32 having teeth which will mesh with the spur gear 33 on the end of a shaft 3d extending through the side of the camera iii. Keyed to the end of the shaft 3K3 is a knob 35 which may be provided, as at Sli, with indices for measuring the rotation oi the knob 35. As the knob 35 is rotated in one direction it will cause, through its spur gear and the rack 3i, the film gate portion @i to partake of linear movement.

Through the toggle 29 the other nlm gate portion likewise partakes oi the same linear movement but in an opposite direction, thereby changing the length oi the aperture formed between the stubs 25. The rotation of the knob in one direction decreases the size of the aperture 3l, while rotation in the opposite direction correspondingly increases it Within the limits of the length set the toggles it and grooves 2l. The length of this distance 3l may be measured by an appropriate indicia placed at 3G.

In operation, when asrnaller object is being photographed on the nlm i6, a smaller image may be focused thereon and the aperture iii `A according to the invention set forth in the coproviding the complete lm gate aperture.

3. A lm gate having means for permitting exposures of different lengths of film, and consisting of two lm gate pieces in the same plane in cooperative light-tight slidable engagement with each other.

4. A lm gate having means for permitting exposures of diierent lengths of lm, and comprising two substantially identical lm gate L- shaped pieces in the same plane in cooperative light-tight slidable intertting engagement with each other, the edge of the horizontal arm of each piece slidably contacting the side of the vertical leg of the other piece to keep the width of the aperture constant while the length may be varied. f

5. A lm gate having means for permitting exposures of different lengths of film, and consisting of two lm gate pieces in the same plane in cooperative light-tight slidable intertting engagement with each other, and toggle means for causing each of said lm gate pieces to partake of the linear movement of the other parallel to the longitudinal side of the lm gate and in opposite directions.

6. A film gate having means for permitting exposures of diierent lengths of lm, and comprising two lm gate pieces in the same plane in cooperative light-tight slidable intertting engagement with each other, toggle means causing each of said iilm gate pieces to partake of the linear movement of the other in opposite directions, and means for moving one of said film gate pieces in a linear direction parallel to the length o-f the film gate opening.

'7. A i'llm gate having means for permitting exposures of diierent lengths of lm, and comprising two film gate L-shaped pieces'in the same plane in cooperative light-tight slidable interi'ltting engagement with each other, the edge of the horizontal arm of each piece slidably contacting the side of the vertical leg of the other piece to keep the width of the aperture constant while the length may be varied, toggle means causing each of said film gate pieces to partake of the linear movement of the other in opposite directions, and means for moving one of said film gate pieces in a linear direction, said means comprising a rack secured to the vertical leg of one of said film gate pieces, a gear meshed with said rack and means for controllably rotating said gear.

8. A lm gate having means for permitting exposures of different lengths of iilm, and comprising two film gate pieces in cooperative lighttight slidable engagement with each other, each of said pieces including a long, narrow portion and a short, wide butt, said long, narrow portion having an undercut and said short, wide butt having a countersink, the undercut of the long, narrow piece cooperating with the countersink of the short, wide butt of the other film gate to provide the slidable light-tight connection therebetween.

- 9. A lm gate having means for permitting exposures of diierent lengths of lm and comprising two illm gate L-shaped pieces in the same plane forming a complete aperture and in slidable intertting engagement with each other, the edge of the horizontal arm of each piece slidably contacting with the side of the vertical leg of the other piece whereby the width of the aperk3);

ture remains constant while the length may be varied.

10. A lm gate having means for permitting exposures of diierent lengths of nlm and at the same time permitting a predetermined width of film to be exposed, and comprising two fllm gate L-shaped pieces in cooperative light-tight slidable engagement with each other, the edge of the horizontal arm of each L-shaped piece sliding along the vertical leg of the other piece.

11. An adjustable lm gate comprising two L-shaped pieces mounted in the same plane so as to form a rectangular aperture and means for moving said pieces uniformly in opposite directions so that the centerline of the aperture of said lm gate remains fixed irrespective of variations in the size of the aperture as the lm gate is adjusted.

RUPERT H. DRAEGER. 

